Specific objectives of the proposed research are as follows: (1) To use low angle light scattering measurements, made on DNA with an instrument having a laser light source, to test current theories of DNA behavior in solution. (2) To use the instrument for studies of the kinetics of DNA denaturation by following simultaneously the rates of change in both molecular weight and shape. (3) To characterize and describe high molecular weight linear and circular DNA by light scattering, sedimentation, and viscosity measurements. This work will provide fundamental information on the molecular weights, solution behavior and denaturation of high molecular weight DNA.